title: Increased phosphorylation of mTOR is involved in remote ischemic preconditioning of hippocampus in mice.
abstract: Different signaling pathways are involved in tissue protection against ischemia reperfusion (IR) injury, among them mammalian target of rapamycin (mTOR) and related pathways have been examined in many recent studies. Present study evaluated the role of mTOR in remote ischemic preconditioning (RIPC) of hippocampus. Renal ischemia was induced (3 cycles of 5min occlusion and 5min reperfusion of unilateral renal artery) 24h before global brain ischemia (20min bilateral common carotid artery occlusion). Saline or rapamycin (mTOR inhibitor; 5mg/kg, i.p.) was injected 30min before RIPC. mTOR and phosphorylated mTOR (p-mTOR) expression, superoxide dismutase (SOD) activity and retention trial of passive avoidance test were determined 24h after global ischemia. Apoptosis and neuronal cell density were assessed 72h after hippocampal ischemia. RIPC decreased apoptosis (p<0.05 vs. IR), improved memory (p<0.05 vs. IR), and augmented p-mTOR expression and SOD activity after hippocampal ischemia (p<0.05 vs. IR). Rapamycin abolished all protective effects of RIPC (p<0.05 vs. RIPC+IR) suggesting a role for mTOR in RIPC induced hippocampal protection.
authors.affiliation: Physiology Research Center, Iran University of Medical Sciences, Tehran, Iran.
authors.forename: Fatemeh
authors.initials: F
authors.lastname: Zare Mehrjerdi
authors.forename: Nahid
authors.initials: N
authors.lastname: Aboutaleb
authors.forename: Rouhollah
authors.initials: R
authors.lastname: Habibey
authors.forename: Marjan
authors.initials: M
authors.lastname: Ajami
authors.forename: Mansoureh
authors.initials: M
authors.lastname: Soleimani
authors.forename: Maedeh
authors.initials: M
authors.lastname: Arabian
authors.forename: Somayeh
authors.initials: S
authors.lastname: Niknazar
authors.forename: Sayed
authors.initials: S
authors.lastname: Hossein Davoodi
authors.forename: Hamidreza
authors.initials: H
authors.lastname: Pazoki-Toroudi
mesh_terms: D000818:Animals; D015153:Blotting, Western; D002545:Brain Ischemia / Q000378:metabolism*; D004195:Disease Models, Animal; D006624:Hippocampus / Q000098:blood supply* / Q000378:metabolism*; D020287:In Situ Nick-End Labeling; D019194:Ischemic Preconditioning; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D010766:Phosphorylation; D058570:TOR Serine-Threonine Kinases / Q000378:metabolism*
chemical_list: C546843:mTOR protein, mouse; D058570:TOR Serine-Threonine Kinases
keywords: ATP sensitive potassium channels; Apoptosis; CCA; Common carotid artery; IR; Ischemia reperfusion; KATP; MAPK; Mammalian target of rapamycin; Memory; Mitochondrial ATP sensitive potassium channels; Mitogen activated protein kinases; PAT; Passive avoidance test; RIPC; ROS; Rapa; Rapamycin; Reactive Oxygen Species; Remote ischemia preconditioning; Remote ischemic preconditioning; SOD; Superoxide dismutase; mKATP; mTOR